$\dfrac{1}{2} + \dfrac{3}{10} = {?}$
Answer: ${\dfrac{1}{2}}$ ${\dfrac{3}{10}}$ $+$ ${\dfrac{1 \times 5}{2 \times 5}}$ ${\dfrac{3 \times 1}{10 \times 1}}$ $+$ ${\dfrac{5}{10}}$ ${\dfrac{3}{10}}$ $+$ $ = \dfrac{{5} + {3}}{10} $ $ = \dfrac{8}{10}$